Transmission control switch



June

Filed Jan. 21', 1949 3, 1952 T. M. BALL TRANSMISSION CONTROL SWITCH 2SHEETS-SHEET l 1N V EN TOR.

June 3, 1952 -r. M. BALI. 2,599,425

TRANSMISSION CONTROL SWITCH Timmy-Jan. 21, 1949 2 srmETs-sx-IEET 2 INVENTOR.

E. E. mams ma WMM Patented June 3, 1952 TRANSMISSION CONTROL SWITCHThomas M. Ball, Detroit, Mich., assignor to Chrysler Corporation,Highland Park, Mich., a

corporation of Delaware Application January 21, 1949, serial No. 71,871

6 Claims. l

rlhis invention relates to a transmission control mechanism for anautomotive vehicle and more particularly to means to control theinitiation of a change in transmission speed ratio drive.

Reference will be made herein to a relatively fastspeed drive which isusually the cruising drive for a vehicle. This may, for example, be aone to one driving speed ratio known as a direct drive or an overdrive.Reference will also be made to a relatively slow speed drive which is avehicle accelerating speed ratio drive and may be a torque multiplyingdrive or where an overdrive is provided for the relatively fast speeddrive the relatively slow speed drive may be a direct drive. The termkickdown, as used herein, refers to a downshift or step-down in thetransmission as, `for example, a downshift from the relatively fastspeed drive to the relatively slow speed drive.

In automotive vehicles having automatic controls associated withvariable speed ratio transmissions it has been found desirable toprovide means responsive to control by the operator for reverting to arelatively slow speed drive when the operator is confronted With anemergency demanding fast acceleration. Such means have usually includeda solenoid actuator and controls therefor including a switch which isarranged to cooperate with the engine carburetor throttle controlmechanism so as to cause a change in speed ratio drive of the vehiclewhen the usual accelerator pedal is depressed to a predeterminedposition. It has also been found with such arrangements that undercertain conditions as where the Vehicle is traveling at a comparativelyhigh rate of speed the transmission cannot be safely operated in arelatively slow speed drive as above described due to the excessiveengine speed which would be required. Means have heretofore beenprovided for limiting the operation of such controls to those engine andvehicle speeds in which a relatively slow speed drive may be safelyaccommodated.

t is an object of this invention to provide a control for a variablespeed ratio transmission by means of which a solenoid actuatorassociated with the transmission may be actuated to effect a change intransmission speed ratio drive by positioning the throttle controllinkage in a predetermined position and to associate with this controla'means to maintain the condition of the control so established afterthe throttle control linkage has retracted from the above predeterminedposition. The speed ratio drive effected by the solenoid is thusmaintained after the throttle control linkage has been moved from theabove predetermined position.

Latching means adapted to accomplish the above purpose are described andclaimed in the copending applications of Louis B. Forman, Serial No.71,933, led January 21, 1949 and Ira M. Holmes, Serial No. 71,874, iiledJanuary 2l, 1949, now Patent No. 2,574,787.

It is an object oi my invention to provide a latching means whichconstitutes an improvement over the mechanism described in the Formanapplication. My improved apparatus possesses advantages of simplicityand economy.

The transmission illustrated and described in Patent No. 2,348,763,issued on May 16, 1944 to A. J. Syrovy et al. and the copendingapplication, Serial No. 374,674 of Neracher et al. are examples oftransmissions to which the controls to be described herein may beapplied.

In the drawings:

Fig. l is a diagrammatic view showing a portion of an automotive engineincluding a carburetor and a power transmission with the presentinvention applied thereto;

Fig. 2 is an enlarged sectional view illustrating the control mechanismapplied to the carburetor shown in Fig. 1; a portion of the carburetorbeing broken away;

Fig. 3 is a side elevation of the carburetor and control of Fig. 1;

Fig. 4 is a partial elevation of the device illustrated in Fig. 3; and

Fig. 5 is a section on the line 5--5 of Fig. 4.

Certain abbreviated terminology will be adopted herein to facilitate thedescription of the invention. The means associated with the throttlecontrol linkage and which is adapted to cause a relatively slow speeddrive to be effected will be hereinafter referred to as a kickdowncontrol. The means which limits the operation of the kickdown control tocertain engine and vehicle speeds will be referred to as an upper limitcontrol.

It is apparent that the control desired herein should be associated withsome manipulation of the throttle linkage which will signal theoperators desire for an upshift and yet permit some latitude of vehicleoperation with respect to engine speed during the relatively slowspeeddrive. Ilhel control, therefore, should be designed to initiate anupshift as the throttle is brought towards a throttle closing positionbeyond the lower limit of throttle opening that would normally bedesired in the operation of the vehicle in its relatively slow speeddrive.

The numeral I c generally indicates an internal combustion engine havingan intake manifold I2 on which is mounted a carburetor I4. Thecarburetor is provided with a conventional throttle valve l5 (Fig. 3)which is adapted to be manipulated by movement of an accelerator pedalI6. The pedal I6 is yieldably urged to its throttle closing position bya spring i6. Pedal i6 which is pivotally mounted at 26 has linkageoperatively connected thereto for remote control of the throttle andthis linkage is indicated by the numerals 22`., 24, 26, 28 and shaft 36.

A variable speed ratio transmission has been generally indicated by thenumeral 32 and is positioned rearwardly of the engine I6 arid adapted totransmit drive from the engine I6 to a propeller shaft (not shown). U S.Patent No. 2,348,763 and copending application, Serial No. 374,674,illustrate transmissions which could be controlled by the apparatus tobe described herein. A solenoid actuator 34 illustrated as mounted onthe side of the transmission 32 may be associated with the transmissioncontrol apparatus so that energization of the solenoid actuator 34 willeffect a kickdown or downshift of the transmission to a relatively slowspeed drive. Deenergizationof the solenoid actuator 34 may be utilizedto eifect an upshift of the transmission to a relatively fastv speeddrive.

In Fig. 1 a typical circuit with which my invention may be associatedfor the control of the energization. of solenoid actuator 34 has beenillustrated as including a vehicle storage battery '36 which is groundedat 38. the battery includes va conductor connecting the battery to thesolenoid actuator 34, a conductorrr31 connecting solenoid actuator 34 toa ygrounded vehicle speed responsive governor 43 having terminals 40 and145 and switch means f 39 to electrically connect these terminals whenthe vehicle vspeed is less than a predetermined value. The circuit valsoincludes a grounded kick- `downcontrol switch 42 incorporating myinvention and connected by a conductor 4| to the conductor 31 so thatthe governor switch 39 and kickdownswitch 42 are in parallel.` Theswitches 39 and 42 are each operable when closed to 'ground the circuit.The governor 43 may be of any suitable design which is operativelyconnected to a driven portion of the transmission or other vehicle speedresponsive members. y Operation of the kickdown control to -be discussedherein is limited to those occasions on which the predetermined vehiclespeed controlling the governor 43 has been exceeded so that :the`terminals 40 and 45 are not electrically connected. A kickdown controlis not necessary below thispred'etermined speed as the governor switch39 provides an energization of solenoid actuator 34 .and a relativelyslow speed drive.

The kickdown4 control switch 42 is illustrated in detail in Figure 2. Anelectrical conductor 4|, previously referred to, is connected with a rstconductor 'terminal y44 which is electrically insulated'at 46 from thesupporting carburetor parts. Ay movable contacting conductor 48 ofsilver or other suitable material is connected to and extends downwardlyfrom a piston 56. The

conductorA 48 is free from engagement with the first terminal v44prior'to operation of the kickdown control mechanism as hereinafterdescribed. Conductor '48 is sufficiently resilient so that itv can beflexed into contact with the terminal 44 and will assume its Figure 2position again when the'par'ts are in position as shown.

The piston 56 which. is the movable portion of the upper limit controlpreviously referred to is freeto slide in a cylinder 52Landvis urgeddownwardly therein by a spring 54 Vuntil the The .A circuit from fpiston engages the insulation 46. The upper end of the piston is open toreceive the spring 54 and the interior of cylinder 3U is connected by apassage 56 to the engine intake at the atmospheric side of the throttlevalve l5 so that the piston is always subjected to the vacuum existingon the atmospheric side of the throttle valve. It is preferable if thepassage 56 is connected to the throat of the conventional carburetorventuri (not shown).

The spring 50 yieldably urges the piston 54 downwardly to the positionillustrated in Figure 2 to position the contact l48 in line with thefixed terminal 44 for engagement therewith under the influence of thecontrol mechanism unless the vacuum in the intake and passage 56 is'sufficient to withdraw piston 50 and contact 48 upwardly out ofalignment with the terminal 44.

Means are provided herein which are responsive to operation of thethrottle control mechanism during a portion of its throttle openingmovement and preferably during that portion thereof when the acceleratorpedal I6 is brought to its fully depressed position corresponding toapproximately full open position of the throttle valve I5, or anovertravel of the pedal beyond the full open throttle valve position, toground the conductor 44 through contact 48. A plungerlike member 60 isslidably mounted in a cylinder 62 formed in the housing of switch 42. Asecond plunger-like member 64 is slidably received in a bore 66 providedin member 60. The members 60 and 64 are retained againrelativelseparation in an axial direction by an enlarged portion 68 ofthe member 64 cooperating with an inwardly directed vflange 10 carriedby the member 6B. The members 6U Vand 64 are yieldably urged to theirFigure 2 position by a relatively heavy spring 'I2 which is positionedin cylinder 62. A spring 16 interposed directly between the members 60and 64 urges the enlarged portion of the member 64 to the left as viewedin Figure 2 against the flange 10 of the member 6l). The lever 28 whichforms a part of the linkage connecting the accelerator pedal with thethrottle. valve, and which was 'previously referred to, i's illustratedin Figure 3 as provided with an extension adapted to contact theexterior end of member 60 when the pedal is depressed s'o that thethrottle valve l5 is in substantially wide open throttle position.y Ifdesired, the contact of extension 86 with member 60 may be adjusted tooccur in response to an overtravel of the pedal `|6 beyond full openthrottle position. y In *either event the extension 48U applies an axiall.force tending to move the member 6D to the left in Fig. 2 in responseto contact of these parts. This movement occurs against the oppositionof spring '(2 andthe plungerv like member 64 is yieldably forced to theleft in Fig. l2 byspring v'I6 until it exes the contact t'erminallu48into contact with the terminal 44. The conductor 4I is thus groundedthrough 44, 48 64 and the parts within the bore VG2 which are inelectrical connection with the carburetor casing. V

When, however, the vacuum onvthe atmospheric side `ofthe throttle valveis sufficient to draw the Ypiston 50 lupwardly against the force of thespring 54 and thereby dispose the contact 43 out of alignment with metermini 44 depression of the accelerator pedaljl as ,aforesaid will notresult in formation'of the grounded electric circuit for the parts areso arranged that the plunger like member 6'4 does nothave sufficientstroke under such circumstances to engage the terminal 44. A suitablestop 'I8 in the form of a shoulder on the switch housing is provided tolimit the movement of the members 60 and 64.

Kickdown switches and upper limit control switches generally arerecognized as devices heretofore employed in the art. However, incertain transmissions it is desirable to provide means for retaining themember 64, contact 48 and terminal 44 in electrical contact after theaccelerator pedal I6 has initiated a kickdown and subsequently beenretracted to a more modified throttle opening position. Therefore, Ihave found it desirable to provide a reduced end portion 82 on themember 68. This construction provides a shoulder 84 so located withrespect to the axis of the member 6U that it comes substantially in theplane of the external surface of the switch housing when the member 60is moved to the left by the extension 80 of throttle control linkage 29.Plate 86 which is adapted to cooperate with the shoulder 84 is pivotallymounted at 88 on the exterior of the switch housing in a plane normal tothe axis of the member 6G. The plate 86 is provided with a slot 90 and ascrew 92 extends through the slot and is secured to the switch housing.The arcuate slot 98 serves as a guide for pivotal movement of the plateS6 in the plane transverse to the axis of member 69. The plate 86 isalso provided with an opening 94 which is preferably located between thepivot 88 and the slot 98. The opening 94 has a diameter greater than thediameter of the larger extended portion of member 60 so that the axialmovement referred to may be accommodated by movement of member 60through the opening 94. The member 68 and the switch housing arepreferablyprovided with cooperating shoulders 96 and 98 which limit theextent of movement of member 6D to the right as shown in Fig. 2. Aspring |80 is positioned to react between plate 86 and the switchhousing to normally urge the plate 86 to pivot or rotate in a clockwisedirection in Fig. 4. It will be seen that this normally does not impairmovement of member 60 until the shoulder 84 passes through the opening94, at which time the clockwise movement of plate 86 under the inuenceof spring |00 causes the member 6D to be locked in position. Thisposition corresponds to the extreme position assumed during its movementto the left in Fig. 2. This movement occurs under the influence ofmember 28 of the throttle control linkage and the shoulder 84 is sopositioned that it passes through the opening 94 at the time when themember 64 is in contact with the contact 48 and the latter is in contactwith the contact 44. The switch components are thus retained in theswitch on position irrespective of subsequent movements of the throttlelinkage.

In order to provide a means for opening the switch when an upshift isdesired the lever 28 of the throttle control linkage is provided with anextension |02 having a cam element |04 formed thereon which is adaptedto engage a portion of plate 86 when the throttle control linkage isretracted to a predetermined position. This predetermined position ispreferably a position corresponding to a substantially closed throttlecondition. The cam element |84 induces a counterclockwise rotation ofplate 86 as an incident to retraction of the throttle control linkage.Sufficient counterclockwise rotation of plate 86 will realign opening 94with the larger extended portion of member 60 so that the member 68 mayextend through the opening 94 and be moved to the right in Fig. 2 underthe influence of spring 12 until shoulders 96 and 98 engage therebyinterrupting the electrical circuit, deenergizing solenoid actuator 34and inducing an upshift in the transmission speed ratio drive. It isassumed of course that the governor switch is open at this time for itis only under these conditions that an operator would require the switch42 to initiate an upshift.

Iclaim:

l. A control for an electrical circuit of a motor vehicle having athrottle and linkage operable to control the throttle; said controlincluding a switch having a member movable to rst and second positionsand one of said positions effecting an electrical closing of saidswitch, spring means urging said member to one of said positions, meansassociated with the motor vehicle throttle control linkage and operableto move said member to the other of said positions as an incident tomovement of said linkage beyond a first predetermined position, lockingmeans operable to retain said member in one of said positions andcomprising an element pivotally mounted on said switch for rotationabout its pivot between rst and second limits and operable to obstructmovement of said member toward one of its said positions when positionedat said rst limit, spring means urging said element toward one of itslimits and means associated with said throttle control linkage andoperable to oppose said spring means and move said element toward theother of its limits as an incident to movement of said linkage beyond asecond predetermined position.

2. A control for an electrical circuit of a motor vehicle; said controlincluding a switch having a member movable to a rst position effectingan electrical closing of said switch and a second position effecting anopening of said switch, a i'lrst means urging said member to said secondposition, mechanical means operable by the vehicle driver to move saidmember to said rst position, locking means operable to retain saidmember in said rst position and comprising an element rotatably mountedon said switch for movement between first and second limits and operableto obstruct movement of said member toward its second position whenpositioned at said rst limit, spring means urging said element towardits first limit and third means operable by the vehicle driver toselectively oppose said spring means and move said element toward 'itssecond limit.

3. A control for an electrical circuit of a motor vehicle having athrottle and linkage operable to control the throttle; said controlincluding a switch having a movable member, means associated with themotor vehicle throttle control linkage and operable to move said memberto a switch closing position as an incident to movement of said linkagebeyond a predetermined limit in a direction tending to open the Vehiclethrottle, an element rotatably mounted on said switch, spring meansurging said element to rotate in a first direction, cam means associatedwith said throttle control linkage and operable to rotate said elementin a second direction as an incident to movement of said linkage beyonda second predetermined position in a direction tending to close saidthrottle, said mem- Aber being provided with a "surface adapted to Ibe'engaged fb'y said element when the -latter "is ro- -tated in its firstdirection and said member is in its switch closing position thereby -tolock said member in its switch `closing position until re- `leased bysaid cam means.

4. A control for an electrical 4circuit of a lmotor vehicle having athrottle and linkage loperable to control the throttle; `said Acontrolinclud'- ing a switch having a housing, a Vrst contact element and asecond contact element, said 'second -contact element having a portionVthereof formed as a plunger and being slidably mounted in said switchhousing for movement Ibetween a rst position remote from said rst*contact lelement and a second position in electrical conductingrelationship with said nrst Contact element, spring means normallyurging Asaid-second contact element to lits rst position, meansassociated with said -linkage and-operable to Aslide said plunger tosaid second position when said linkage is moved beyond a predeterminedposition in a direction tending to open said throttle, a plate pivotallymounted on said housing, a member secured to -said housing 'and `havinga portion overlying said plate to maintain said plate normal to itspivotal axis, said plate Yhaving an opening through which said plungerextends, said plunger having an indentation so positioned thatit-isaligned with said-plate when said plunger is in its second position,spring means associatedwith said plate and urging the latter'to rotateso that a-portion thereof adjacent said opening `is received insaid'indentation when said plunger is in its second position anda cammeans carried by-'said `linkage and operable to engage a portion of saidvplate to pivot 'said plate in a direction to 'remove said plate portionfrom said indentation and `release 'said plunger lfor return to its rstposition under `the inuence -of said rst mentioned spring means, saidlcarn means being sopositioned 'as toeng'agesaid plate in `response to'movement of said 'linkage beyond a predetermined limit ina directionVtending to close said throttle.

5. AA control for-an'electrical'circuit of a'motor -vehicle having 'athrottle and linkage operable to-control the throttle ;v said controlincluding a switch having a "housing, a rst contact element and a secondcontact element, sai'dsecond contact element having `a yportion 'thereoflformed as'a plunger and being slidably mounted in said switch housingfor -movement between 'a first position remote from said rs't contactelement and a second positionin electrical conducting relationship withsaid -firstcontact element, spring means normally urgingsaidplunger toits rst position, means associated withsaid linkage and operable toslide 'saidplunger to said second position when said linkage is movedbeyond a predetermined `position in a 4direction tending to open `saidthrottle, a plate pivotally mounted on said housing -in 'a Aplane normalto the axis of said plunger, said plunger lhaving a shouldersopositioned thatlitisloc'ated in said plane `when said plunger is in itssecond position, separate spring means associated with said plate 4andurging the latter to rotate so that a portion thereof Vabuts saidshoulder when said plunger is in its second position to lock it thereinand a cam means carried by said linkage and operable to engage a portionof said plate to pivot said plate away from said shoulder and releasesaid plunger for return to its first position under the influence ofsaid rst mentioned spring means, said cam means being so positioned asto engage said plate in response to movement of said linkage beyond apredetermined limit in a direction tending to close said throttle.

6. A control for an electrical circuit of a motor vehicle having athrottle and linkage operable to control the throttle; said controlincluding a switch having a housing, a rst contact element and a secondcontact element, said second contact element having a portion thereofformed as a plunger and being slidably mounted in said switch housingfor movement between a first position remote from said rst contactelement and a second position in electrical conducting relationship withsaid rst contact element, spring means normally urging said plunger toits first position, means associated with said linkage and operable toslide said plunger to said second position when said linkage is movedbeyond a predetermined position in a direction tending to open saidthrottle, a plate pivotally mounted on the exterior of said. housing ina plane normal Vto the axis of said plunger, said plate having anopening through which one end portion of said plunger extends, saidplunger having an indentation on the surface thereof so positioned thatit is located in said plane when said plunger is in its second position,spring means associated with said plate and urging thelatter to rotateso that the opening ytherein is disaligned with said plunger and aportion of the plate adjacent said opening cooperates with saidindentation when said plunger is in its second position to lock'ittherein and a cam means carried by `said linkage and operable to engagea portion of said plate to pivot said plate and realign the openingtherein with said plunger and release said plunger for return to itsfirst position under the influence of said Afirst mentioned springmeans, said cam means being so positioned as to engage said plate inresponse to movement of said linkage beyond a predetermined limit in a.direction tending to close said throttle.

THOMAS `M. BALL.

REFERENCES CITED The following references are of record `in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,974,991 Hutt Sept. 25, 19342,396,551 Boyce Mar. 12, 1946

